Pulse of the Planet
is a weekday radio
show that "provides its listeners with a two-minute sound portrait of Planet
Earth, tracking the rhythms of nature, culture and science worldwide and
blending interviews and extraordinary natural sound."

Divers exploring the depths of underwater caves
have made a startling discovery —primitive animals
whose ancestors have been swimming in the darkness
for millions of years. I’m Jim Metzner, and this is
the Pulse of the Planet.

Dr. Tom Iliffe is a professor of marine biology
at Texas A&M University. He and other researchers
have explored hundreds of deep saltwater caves
around the world in such places as Hawaii and the
Yucatan Peninsula. He describes a dive into one of
these caves as a trip back in time.

“Many of the animals that we find there are
essentially living fossil species. They’re really
very primitive forms of life that probably have
existed on Earth for tens of millions of years and
been isolated. These are animals that have adapted
to life in the caves. They have lost their eyes,
they have lost their pigment, features that they
really don’t need in the totally lightless
underwater caves.

One tiny animal, called Remipedia, may have
existed in these pitch-black depths since the days
of the dinosaur.

“One of the most interesting animals that we’ve
found in these underwater caves is a very primitive
type of crustacean called Remipedia. Remipedia is a
new class of Crustacea. It’s like nothing else
that’s known on earth. Superficially it looks like a
centipede, and it does spend all it’s life swimming
endlessly through the cave waters. And it’s nearest
relatives perhaps are known only from fossils that
may date back fifty million years or more.”

In a future program, we’ll hear how one species
of living fossil came to be found in two different
caves on opposite ends of the earth.